1. Field of the Invention
The invention relates to a machine tool, and in particular to a milling and drilling machine comprising a rigid base on which an inclined support surface directed forward/upward is formed. The machine further includes at least one workpiece support rotatable about the central axis of the support surface, and a support supported on the support surface that is rotatable about its central axis.
2. Discussion of the Related Art
EP 0 721 819 B1 discloses a known milling and drilling machine for machining a workpiece in a plurality of axes. This machine comprises a machining unit shiftable along coordinate axes on a rigid machine column by means of a motor and included vertical spindle head. The front surface of the machine includes a column recess, the bottom of which extends forward and upward by 45° and serves as a support surface for the support of a workpiece support. The support is rotatable about the central axis of the support surface, which is inclined by 45°. As viewed from above, the support comprises a circular foot and a support shoulder formed integrally therewith. A support surface formed on the support shoulder is inclined by 45° with respect to the rotational axis of the support, and serves as a support surface for a workpiece table. The workpiece table may be formed as a round table rotatable about its central axis by means of a motor.
The column recess and its bottom extend forward and upward by 45°. The column recess and the workpiece support are rotatably supported thereon and are disposed on the machine column in its vertical central plane. By rotating the workpiece support about its central axis on the support surface, the workpiece table can be rotated into a horizontal machining and clamping position, a vertical position, and an intermediate position. The workpiece support can be fixed in each of these positions so that a clamped workpiece can be machined, by means of the vertical spindle, in a plurality of axes. However, no back surface undercuts may be produced with this machine.
Other machine tools comprise workpiece supports rotatably disposed on a surface inclined by 45° are, for example, disclosed in DE 3 590 093 T and U.S. Pat. No. 4,644,635. On these machines, the workpiece table can also be moved from a horizontal position into a vertical position by means of a motor. This allows the clamped workpiece to be machined vertically and horizontally.